Differences in the biochemical properties of aldrin epoxidase, a cytochrome P-450-dependent monooxygenase, in various tissues.

Aldrin epoxidase, a cytochrome P-450-dependent monooxygenase, was studied in the lung and kidney of male rats. The sensitivity of the liver enzyme activity to different chemicals in vitro was influenced by the treatment of the animals with phenobarbital or methylcholanthrene. These results confirm that more than one form of cytochrome P-450 supports aldrin epoxidase in the liver. The lung and kidney aldrin epoxidase activity was not modified by the administration of chemical inducers to the rats. In vitro, the lung and kidney aldrin epoxidase activities were activated by tetrahydrofurane and progesterone, respectively. The results obtained from the lung and kidney indicate that one single species of cytochrome P-450, associated with aldrin epoxidase, exists in these organs, but it may be a different type, or regulated in a different manner in these tissues.

Study of lung reactions in six asymptomatic workers occupationally exposed to hard metal dusts.

The description of one case of pulmonary fibrosis in a group of workers occupationally exposed to hard metal dusts with high concentrations of cobalt (50-90%), followed for five years, prompted us to perform a cytological examination on the bronchoalveolar lavage fluid plus determination of the lymphocytic subpopulations in six asymptomatic workers with the longest exposure. Bronchoalveolar lavage performed 16 hours (3 cases) or 48 hours (3 cases) after the end of the workshift showed a lymphocytosis with inversion of the helper/suppressor ratio in 3 cases. This demonstrates an immune response at deep lung level. No difference was observed between a subject with ascertained interstitial fibrosis and the other subjects. Furthermore, bronchoscopy revealed marked inflammatory reaction of the tracheobronchial mucosa.